Air Conditioning
The A/C refrigerant system is a clutch cycling orifice tube type. The system components include:- A/C compressor
- A/C clutch
- A/C condenser core
- A/C evaporator core
- A/C suction accumulator
- connecting refrigerant lines
The refrigeration system operation is controlled by the:
- A/C evaporator core orifice
- evaporator air discharge temperature sensor
- A/C compressor pressure relief valve
- dual function pressure switch
- low charge protection switch
The refrigerant system incorporates an A/C compressor controlled by an evaporator air discharge temperature sensor.
The evaporator air discharge temperature sensor senses the A/C evaporator core temperature to control A/C compressor operation.
An A/C compressor pressure relief valve is installed in the A/C manifold and tube to protect the refrigerant system against excessively high refrigerant pressures.
The A/C evaporator core orifice is installed in the condenser to evaporator tube to meter the liquid refrigerant into the A/C evaporator core.
FS-10 A/C Compressor:
A/C Compressor and Clutch Assembly
NOTE:
- Internal A/C compressor components are not repaired separately. The FS-10 A/C compressor is repaired only as an assembly. The A/C clutch, A/C clutch pulley, A/C clutch field coil and the shaft seal are repairable.
- Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
The FS-10 A/C compressor has the following characteristics:
- A ten-cylinder swashplate design utilizing the tangential design mount.
- A one-piece lip-type seal (installed from the front of the A/C compressor) is used to seal it at the shaft opening in the assembly.
- Five double-acting pistons operate within the cylinder assembly. The pistons are actuated by a swashplate that changes the rotating action of the shaft to a reciprocating force.
- Reed-type discharge valves are located between the cylinder assembly and the head at each end of the A/C compressor.
- The A/C compressor uses PAG oil or equivalent. This oil contains special additives required for the A/C compressor.
- The A/C compressor oil from vehicles equipped with an FS-10 A/C compressor may have a dark color while maintaining a normal oil viscosity. This is normal for this A/C compressor because carbon from the piston rings will discolor the oil.
A/C Compressor Clutch Assembly:
The magnetic A/C clutch has the following characteristics:
- The A/C clutch drives the compressor shaft.
- When battery positive voltage (B+) is applied to the A/C clutch field coil, the clutch plate and hub assembly is drawn toward the A/C clutch pulley.
- The magnetic force locks the clutch plate and hub assembly and the A/C clutch pulley together as one unit, causing the compressor shaft to rotate.
- When B+ is removed from the A/C clutch field coil, springs in the clutch plate and hub assembly move the clutch plate away from the A/C clutch pulley.
A/C Compressor Pressure Relief Valve
An A/C compressor pressure relief valve is incorporated in the compressor A/C manifold and tube to:
- relieve unusually high refrigerant system discharge pressure buildups.For information regarding operating pressure(s) specifications, refer to Specifications.
- prevent damage to the A/C compressor and other system components.
- avoid total refrigerant loss by closing after the excessive pressure has been relieved.
A/C Condenser Core
NOTE: Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
The A/C condenser core has the following characteristics:
- It is an aluminum fin and tube design heat exchanger located in front of the vehicle radiator.
- It cools compressed refrigerant gas by allowing air to pass over the fins and tubes to extract heat and by condensing gas to liquid refrigerant as it is cooled.
Refrigerant Lines
NOTE: Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
The aft condenser to evaporator tube contains the A/C evaporator core orifice. When the A/C system is in operation:
- there is high pressure liquid refrigerant upstream of the A/C evaporator core orifice.
- there is low pressure liquid refrigerant downstream of the A/C evaporator core orifice.
The forward condenser to evaporator tube is equipped with a serviceable high pressure A/C charge valve port.
The evaporator to accumulator/drier suction line contains low pressure refrigerant gas and is equipped with a serviceable low pressure A/C charge valve port.
The A/C manifold and tube is attached to the A/C compressor, is sealed with O-ring seals, and has the following features:
- The upstream side contains low pressure refrigerant gas and an integral non-serviceable muffler.
- The downstream side contains high pressure refrigerant gas and an integral non-serviceable muffler.
- The downstream side also contains a serviceable A/C compressor pressure relief valve and a fitting used to mount the A/C pressure transducer. A long-travel Schrader-type valve stem core is installed in the fitting so that the A/C pressure transducer can be removed without discharging the A/C system.
A/C Evaporator Core
NOTE:
- Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
- The evaporator core is serviced as a core and housing assembly. The evaporator core internal doors, seals and door linkage are included with the housing.
The A/C evaporator core is the plate/fin type with a unique refrigerant flow path.
- A mixture of refrigerant and oil enters the bottom of the A/C evaporator core through the A/C evaporator core inlet tube and then moves out of the A/C evaporator core through the A/C evaporator core outlet tube.
- This flow pattern accelerates the flow of refrigerant and oil through the A/C evaporator core.
A/C Evaporator Core Orifice
NOTE: A new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed.
The A/C evaporator core orifice has the following characteristics:
- It is located in the aft condenser to evaporator tube.
- It has filter screens located on the inlet and outlet ends of the tube body.
- The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice.
- O-ring seals on the A/C evaporator core orifice prevent the high-pressure liquid refrigerant from bypassing the A/C evaporator core orifice.
- Adjustment or repair cannot be made to the A/C evaporator core orifice assembly. It must be installed as a unit. The evaporator core orifice can be accessed by separating a fitting in the condenser to evaporator line.
An A/C evaporator core orifice or O-ring seal is not considered a major component but a new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed for lack of performance.
Suction Accumulator/Drier
NOTE: Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
A new suction accumulator should be installed if one of the following conditions exist:
- The suction accumulator is perforated.
- There is evidence of moisture in the system such as internal corrosion of metal refrigerant lines or the refrigerant oil is thick and dark.
The suction accumulator/drier is mounted to the A/C accumulator bracket to the right of the vehicle centerline. The inlet tube of the suction accumulator/drier is attached to the evaporator to accumulator/drier suction line. The outlet tube attaches to the evaporator to compressor suction line.
After entering the inlet of the suction accumulator/drier, heavier oil-laden refrigerant contacts an internally mounted dome (which serves as an umbrella) and drips down onto the bottom of the canister.
- A small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated heavier liquid refrigerant and oil mixture to re-enter the compressor suction line at a controlled rate.
- As the heavier mixture passes through the small diameter liquid bleed hole, it has a second chance to vaporize and recirculate through the A/C compressor without causing compressor damage due to slugging.
- A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out refrigerant system contaminant particles.
- A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.
- A fitting located on the top of the suction accumulator/drier is used to attach the A/C cycling switch. A long-travel Schrader-type valve system core is installed in the fitting so that the A/C cycling switch can be removed without discharging the A/C system.
Low Charge Protection Switch
The low charge protection switch is used to prevent A/C compressor damage in the event of a low refrigerant charge.
- The electrical switch contacts open when the suction pressure drops below normal levels. The contacts close when the suction pressure rises.For information regarding operating pressure(s) specifications, refer to Specifications.
- When the low charge protection switch contacts open, the A/C clutch field coil is de-energized and compressor operation stops.
- The low charge protection switch is mounted on a Schrader valve-type fitting on the top of the suction accumulator/drier.
- A valve depressor, located inside the threaded end of the low charge protection switch, presses in on the Schrader valve stem, allowing the suction pressure inside the suction accumulator/drier to control the operation of the low charge protection switch.
- It is not necessary to discharge the refrigerant system to remove the low charge protection switch.
Pressure Cutoff Switch, Dual Function
The dual function pressure switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.
- The dual function pressure switch is mounted on a schrader valve-type fitting on the compressor manifold and tube assembly.
- It is not necessary to recover the refrigerant to install a new dual function pressure switch.
- A valve depressor, located in the threaded end of the dual function pressure switch, presses on the valve stem. This allows the dual function pressure switch to monitor the compressor discharge pressure.
- When the compressor discharge pressure rises, the switch contacts open, disengaging the A/C compressor. When the compressor discharge pressure drops, the switch contacts close to allow operation of the A/C compressor. For information regarding operating pressure(s) specifications, refer to Specifications.
- The dual function pressure switch has a second set of electrical contacts used for high-speed cooling fan control. When the compressor discharge pressure rises, the contacts close and engage the high-speed cooling fan control. When the pressure drops, the contacts open and the high-speed cooling fan control is disengaged.
Spring Lock Coupling:
Spring Lock Coupling
The spring lock coupling is a refrigerant line coupling held together by a garter spring inside a circular cage.
- When the coupling is connected together, the flared end of the female fitting slips behind the garter spring inside the cage of the male fitting.
- The garter spring and cage then prevent the flared end of the female fitting from pulling out of the cage.
- O-ring seals are used to seal between the two halves of the spring lock couplings.
- Use only the O-ring seals listed in the Ford Master Parts Catalog for the spring lock coupling.
- A plastic indicator ring is used on the spring lock couplings of the A/C evaporator core to indicate, during vehicle assembly, that the coupling is connected. Once the coupling is connected, the indicator ring is no longer necessary but will remain captive by the coupling near the cage opening.
- The indicator ring may also be used during repair operations to indicate connection of the coupling.
- An A/C tube lock coupling clip may be used to secure the coupling but is not required.
Service Gauge Port Values:
Service Gauge Port Valves
The high-pressure service gauge port valve is located on the high pressure liquid line.
The low pressure service gauge port valve is located on the evaporator to accumulator/drier suction line.
The fitting is an integral part of the refrigerant line or component.
- Special couplings are required for both the high side and low side service gauge ports.
- A new Schrader-type valve core can be installed if the seal leaks.
- Always install the A/C charging valve cap on the service gauge port valves after repairing the refrigerant system.